Langhorne Borough, formerly known as Attleboro, is a borough in Bucks County, Pennsylvania, United States. The population was 1,643 at the time of the 2020 census. The mailing address "Langhorne" is used for Langhorne Borough, but it is also used broadly to describe the majority of surrounding Middletown Township, which for the most part uses Langhorne's ZIP code of 19047. Sesame Place, while physically located in Middletown Township, has Langhorne as its mailing address.